Caution in Generalizing Part D Results to Medicare Population—Reply

Author Affiliations: Division of General Internal Medicine, San Francisco General Hospital, University of California, San Francisco (Drs Millett and Bindman); Department of Primary Care and Public Health, Imperial College, London, England (Dr Millett); and Department of Family Medicine, Medical University of South Carolina, Charleston (Drs Everett, Matheson, and Mainous).

Briesacher and colleagues highlight that we identified a greater reduction in mean out-of-pocket expenditures (32%) among Medicare beneficiaries participating in the MEPS1 than previous studies (range, 13%-18%).2,3 They suggest that this may be partly owing to the longitudinal study design used, which limits the generalizability of our findings to the elderly Medicare population.